How to type Spock's vulcan salute emoji with your iPhone or iPad

How do you type Mr. Spock's live long and prosper (llap) Vulcan salute emoji on your iPhone or iPad?
After posting the iOS 8.3 emoji keyboard how-to earlier, of course this was the question that quickly flooded my inbox. It's part of the same new unicode emoji set Apple has added to iOS 8.3 and OS X 10.10.3, so if you've updated to one or both of those, you can see it. The problem is, Apple hasn't yet added it to the emoji keyboard, so you can't type it. Unless you're logical about it...